/*
 * decode.c
 *
 *  Created on: Jun 6, 2025
 *      Author: 26474
 */

#include "decode.h"
#include "../../iNav_lib/timeSync.h"

UM982_BESTNAV_s um982_bestnav = {0};
UM982_UNIHEADING_s um982_uniheading = {0};

GNSS_RingBuffer_s GNSS_fifo =
{
	.dd = {0},
	.head = 0,
	.tail = 0,
	.dataLen = 0,
	.empty_cnt = 0,
	.size = GNSS_DATA_SIZE
};
DECODE_Monitor_s um982_decode_monitor = {0};
UM982_BINARY_HEADER_MSG_s um982_bin_header_info = {0};

static int cnt = 0;
static int msg_len = 0;
static int crc32_len = 4;
static int um982_binary_header_len = 24;
static uint8_t um982_buffer[GNSS_DATA_SIZE] = {0};
static UM982_DECODE_BINARY_STEP_ENUM UM982_DECODE_BINARY_STEP = HEADER1;

void um982_decode_binary_func(uint8_t rcv)
{
	switch(UM982_DECODE_BINARY_STEP)
	{
		case HEADER1:
			if(rcv == 0xAA)
			{
				cnt = 0;
				um982_binary_header_len = 24;
				um982_decode_monitor.frame_cnt++;

				um982_buffer[cnt++] = rcv;
				UM982_DECODE_BINARY_STEP = HEADER2;
				um982_binary_header_len--;
			}
			else
			{
				UM982_DECODE_BINARY_STEP = HEADER1;
				um982_decode_monitor.check_failed_cnt++;
			}
			break;

		case HEADER2:
			if(rcv == 0x44)
			{
				um982_buffer[cnt++] = rcv;
				UM982_DECODE_BINARY_STEP = HEADER3;
				um982_binary_header_len--;
			}
			else
			{
				UM982_DECODE_BINARY_STEP = HEADER1;
				um982_decode_monitor.check_failed_cnt++;
			}
			break;

		case HEADER3:
			if(rcv == 0xB5)
			{
				um982_buffer[cnt++] = rcv;
				UM982_DECODE_BINARY_STEP = HEADER_INFO;
				um982_binary_header_len--;
			}
			else
			{
				UM982_DECODE_BINARY_STEP = HEADER1;
				um982_decode_monitor.check_failed_cnt++;
			}
			break;

		case HEADER_INFO:
			um982_buffer[cnt++] = rcv;
			if(--um982_binary_header_len == 0)
			{
				memcpy((void*)&um982_bin_header_info, (void*)um982_buffer, 24);
				msg_len = um982_bin_header_info.msgLen;
				if(um982_bin_header_info.leapSec == 18)
				{
					UM982_DECODE_BINARY_STEP = DATA;
				}
				else
				{
					UM982_DECODE_BINARY_STEP = HEADER1;
					um982_decode_monitor.check_failed_cnt++;
				}
			}
			break;

		case DATA:
			um982_buffer[cnt++] = rcv;
			if(--msg_len <= 0)
			{
				crc32_len = 4;
				UM982_DECODE_BINARY_STEP = CRC32;
			}
			break;

		case CRC32:
			um982_buffer[cnt++] = rcv;
			if(--crc32_len <= 0)
			{
				um982_decode_monitor.rcv_checkSum = (uint32_t)um982_buffer[cnt - 1] << 24 | (uint32_t)um982_buffer[cnt - 2] << 16
							   |(uint32_t)um982_buffer[cnt - 3] << 8 | (uint32_t)um982_buffer[cnt - 4];
				um982_decode_monitor.calc_checkSum = CRC32_Checksum((const uint8_t*)&um982_buffer[0], cnt-4);
				if(um982_decode_monitor.rcv_checkSum == um982_decode_monitor.calc_checkSum)
				{
					if(um982_bin_header_info.msgId == 2118)
					{
						um982_decode_monitor.frame_BESTNAVB_cnt++;
						memcpy((void*)&um982_bestnav, (void*)&um982_buffer[24], um982_bin_header_info.msgLen);
						um982_bestnav.gpst.week = um982_bin_header_info.week;
						um982_bestnav.gpst.itow = um982_bin_header_info.itow * 0.001;
						um982_bestnav.is_update = 1;

					}
					else if(um982_bin_header_info.msgId == 972)
					{
						um982_decode_monitor.frame_UNIHEADINGB_cnt++;
						memcpy((void*)&um982_uniheading, (void*)&um982_buffer[24], um982_bin_header_info.msgLen);
						um982_uniheading.gpst.week = um982_bin_header_info.week;
						um982_uniheading.gpst.itow = um982_bin_header_info.itow * 0.001;
						um982_uniheading.is_update = 1;
					}
					um982_decode_monitor.check_ok_cnt++;
				}
				else
				{
					um982_decode_monitor.check_failed_cnt++;
				}
				UM982_DECODE_BINARY_STEP = HEADER1;
			}
			break;

		default:
			UM982_DECODE_BINARY_STEP = HEADER1;
			break;
	}
}



//UM982_DECODE_ASCII_STEP_ENUM UM982_DECODE_STEP = HEADER;
//void um982_decode_func(uint8_t rcv)
//{
//	switch (UM982_DECODE_STEP)
//	{
//		case HEADER:
//			if(rcv == '#' || rcv == '$')
//			{
//				frame_cnt++;
//				cnt = 0;
//				um982_buffer[cnt++] = rcv;
//				UM982_DECODE_STEP = FRAME_TYPE;
//			}
//			break;
//
//		case FRAME_TYPE:
//			um982_buffer[cnt++] = rcv;
//			if(rcv == ',')
//			{
//				if(strncmp((const char*)&um982_buffer[3], "ZDA",3) == 0) // GNZDA或GPZDA 类似GPGGA与GNGGA
//				{
//					UM982_DECODE_STEP = GNZDA;
//				}
//				else if(strncmp((const char*)&um982_buffer[1], "BESTNAVA",8) == 0) // BESTNAVA
//				{
//					frame1_cnt++;
//					UM982_DECODE_STEP = BESTNAVA;
//				}
//				else if(strncmp((const char*)&um982_buffer[4], "HEADINGA",8) == 0)	// UNIHEADING
//				{
//					UM982_DECODE_STEP = UNIHEADINGA;
//				}
//				else
//				{
//					UM982_DECODE_STEP = HEADER;
//				}
//			}
//			break;
//
//		case GNZDA:
//			um982_buffer[cnt++] = rcv;
//			if(rcv == '\r')
//			{
//				rcv_checksum = strtoul((const char*)&um982_buffer[cnt-3], NULL, 16);
//				calc_checksum = NMEA0183_XOR_Checksum((const char*)um982_buffer);
//				if(calc_checksum == rcv_checksum)
//				{
//					decode_GNGDZ_func(um982_buffer, cnt);
//					um982_gnzda.check_ok_cnt++;
//				}
////				else
////				{
////					um982_gnzda.check_fail_cnt++;
////				}
//				UM982_DECODE_STEP = FRAME_END;
//			}
//			break;
//
//		case BESTNAVA:
//			um982_buffer[cnt++] = rcv;
//			if(rcv == '\r')
//			{
//				rcv_checksum = strtoul((const char*)&um982_buffer[cnt-9], NULL, 16);
//				calc_checksum = CRC32_Checksum((const uint8_t*)&um982_buffer[1], cnt-11);
//				if(calc_checksum == rcv_checksum)
//				{
//					decode_BESTNAVA_func(um982_buffer, cnt);
//					um982_bestNav.check_ok_cnt++;
//				}
//				else
//				{
//					um982_bestNav.check_fail_cnt++;
//				}
//
//				UM982_DECODE_STEP = FRAME_END;
//			}
//			break;
//
//		case UNIHEADINGA:
//			um982_buffer[cnt++] = rcv;
//			if(rcv == '\r')
//			{
//				uint32_t rcv_checksum = strtoul((const char*)&um982_buffer[cnt-9], NULL, 16);
//				uint32_t calc_checksum = CRC32_Checksum((const uint8_t*)&um982_buffer[1], cnt-11);
//				if(calc_checksum == rcv_checksum)
//				{
//					decode_UNIHEADINGA_func(um982_buffer, cnt);
//					um982_uniheading.check_ok_cnt++;
//				}
//
//				UM982_DECODE_STEP = FRAME_END;
//			}
//			break;
//
//		case FRAME_END:	// '\n'
//			UM982_DECODE_STEP = HEADER;
//			break;
//
//		default:
//			UM982_DECODE_STEP = HEADER;
//			break;
//	}
//}
//
//void decode_GNGDZ_func(const uint8_t *rcv, int len)
//{
//	uint8_t comma_idx[8];
//	uint8_t comma_cnt = 0;
//	for(int i = 0; i<len; i++)
//	{
//		if(rcv[i] == ',')
//		{
//			comma_idx[comma_cnt] = i;
//			comma_cnt++;
//		}
//	}
//
//	if(comma_cnt == 6)
//	{
//		char tmp_buf[6]; tmp_buf[2] = '\0';
//		tmp_buf[0] = rcv[comma_idx[0]+1]; tmp_buf[1] = rcv[comma_idx[0]+2];
//		utc.hour = atoi((const char*)tmp_buf);
//
//		tmp_buf[0] = rcv[comma_idx[0]+3]; tmp_buf[1] = rcv[comma_idx[0]+4];
//		utc.min = atoi((const char*)tmp_buf);
//
//		tmp_buf[0] = rcv[comma_idx[0]+5]; tmp_buf[1] = rcv[comma_idx[0]+6];
//		tmp_buf[2] = rcv[comma_idx[0]+7]; tmp_buf[3] = rcv[comma_idx[0]+8];
//		tmp_buf[4] = rcv[comma_idx[0]+9]; tmp_buf[5] = '\0';
//		utc.sec = atof((const char*)tmp_buf);
//
//		utc.day   = atoi((const char*)&rcv[comma_idx[1]+1]);
//		utc.month = atoi((const char*)&rcv[comma_idx[2]+1]);
//		utc.year  = atoi((const char*)&rcv[comma_idx[3]+1]);
//		um982_gnzda.decode_ok_cnt++;
//	}
////	else
////	{
////		um982_gnzda.decode_fail_cnt++;
////	}
//}
//void decode_BESTNAVA_func(const uint8_t *rcv, int len)
//{
//	uint8_t comma_idx[40];
//	uint8_t comma_cnt = 0;
//	for(int i = 0; i<len; i++)
//	{
//		if(rcv[i] == ',')
//		{
//			comma_idx[comma_cnt] = i;
//			comma_cnt++;
//		}
//	}
//
//	if(comma_cnt == 38)
//	{
//		gpst.week = atoi((const char*)&rcv[comma_idx[3]+1]);
//		gpst.itow = atoi((const char*)&rcv[comma_idx[4]+1]) * 0.001;
//		um982_bestNav.decode_ok_cnt++;
//	}
//	else
//	{
//		um982_bestNav.decode_fail_cnt++;
//	}
//
//}
//
//void decode_UNIHEADINGA_func(const uint8_t *rcv, int len)
//{
//	um982_uniheading.decode_ok_cnt++;
//}

//uint8_t NMEA0183_XOR_Checksum(const char *nmea_str)
//{
//    if (nmea_str[0] != '$' && nmea_str[0] != '!') {
//        return 0; // 无效NMEA格式
//    }
//    uint8_t checksum = 0;
//    for (const char *p = nmea_str + 1; *p != '*'; p++) {
//        checksum ^= *p; // 逐字符异或
//    }
//    return checksum;
//}

const uint32_t crc32Table[256] =
{
	0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
	0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
	0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
	0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
	0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
	0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
	0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
	0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
	0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
	0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
	0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
	0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
	0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
	0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
	0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
	0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
	0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
	0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
	0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
	0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
	0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
	0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
	0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
	0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
	0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
	0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
	0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
	0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
	0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
	0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
	0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
	0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
	0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
	0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
	0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
	0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
	0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
	0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
	0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
	0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
	0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
	0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
	0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
};

uint32_t CRC32_Checksum(const uint8_t *buf, uint16_t len)
{
	uint32_t CRC32 = 0;
	for (uint16_t idx0 = 0; idx0 < len; idx0++)
	{
		CRC32 = crc32Table[(CRC32 ^ buf[idx0]) & 0xff] ^ (CRC32 >> 8);
	}
	return CRC32;
}
